title: Eubacterial SpoVG homologs constitute a new family of site-specific DNA-binding proteins.
abstract: A site-specific DNA-binding protein was purified from Borrelia burgdorferi cytoplasmic extracts, and determined to be a member of the highly conserved SpoVG family. This is the first time a function has been attributed to any of these ubiquitous bacterial proteins. Further investigations into SpoVG orthologues indicated that the Staphylococcus aureus protein also binds DNA, but interacts preferentially with a distinct nucleic acid sequence. Site-directed mutagenesis and domain swapping between the S. aureus and B. burgdorferi proteins identified that a 6-residue stretch of the SpoVG α-helix contributes to DNA sequence specificity. Two additional, highly conserved amino acid residues on an adjacent β-sheet are essential for DNA-binding, apparently by contacts with the DNA phosphate backbone. Results of these studies thus identified a novel family of bacterial DNA-binding proteins, developed a model of SpoVG-DNA interactions, and provide direction for future functional studies on these wide-spread proteins.
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky, USA.
authors.forename: Brandon L
authors.initials: BL
authors.lastname: Jutras
authors.forename: Alicia M
authors.initials: AM
authors.lastname: Chenail
authors.forename: Christi L
authors.initials: CL
authors.lastname: Rowland
authors.forename: Dustin
authors.initials: D
authors.lastname: Carroll
authors.forename: M Clarke
authors.initials: MC
authors.lastname: Miller
authors.forename: Tomasz
authors.initials: T
authors.lastname: Bykowski
authors.forename: Brian
authors.initials: B
authors.lastname: Stevenson
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites / Q000235:genetics; D001667:Binding, Competitive; D025065:Borrelia burgdorferi / Q000235:genetics / Q000378:metabolism*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005051:Eubacterium / Q000145:classification / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D059372:Nucleotide Motifs / Q000235:genetics; D011485:Protein Binding; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013211:Staphylococcus aureus / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins